Tensegrity: 3V Pars Tetra

Following on from my last post I decided to revisit some of my earlier models to see how they may also exhibit rotational axis symmetry similar to the truncated tetrahedron.
In this case I selected the 3v Pars Tetra mentioned in one of my first postings:

http://spatialgeometrix.blogspot.com/2010/09/tetrahedron-tensegrity.html

 
I took the original model (left) and inserted a cross axis model; similar to before (blue); aligning the centre line axis with the midpoint of the brown struts in each direction and as you can see we can again show rotational symmetry.

We can also show that if we draw a connecting line between the end points of matching pairs of brown struts that this line should pass thru the centre of the assembly.